xref: /petsc/src/mat/impls/aij/seq/crl/crl.c (revision 503c0ea9b45bcfbcebbb1ea5341243bbc69f0bea)
1 
2 /*
3   Defines a matrix-vector product for the MATSEQAIJCRL matrix class.
4   This class is derived from the MATSEQAIJ class and retains the
5   compressed row storage (aka Yale sparse matrix format) but augments
6   it with a column oriented storage that is more efficient for
7   matrix vector products on Vector machines.
8 
9   CRL stands for constant row length (that is the same number of columns
10   is kept (padded with zeros) for each row of the sparse matrix.
11 */
12 #include <../src/mat/impls/aij/seq/crl/crl.h>
13 
14 PetscErrorCode MatDestroy_SeqAIJCRL(Mat A)
15 {
16   Mat_AIJCRL     *aijcrl = (Mat_AIJCRL*) A->spptr;
17 
18   PetscFunctionBegin;
19   /* Free everything in the Mat_AIJCRL data structure. */
20   if (aijcrl) {
21     PetscCall(PetscFree2(aijcrl->acols,aijcrl->icols));
22   }
23   PetscCall(PetscFree(A->spptr));
24   PetscCall(PetscObjectChangeTypeName((PetscObject)A, MATSEQAIJ));
25   PetscCall(MatDestroy_SeqAIJ(A));
26   PetscFunctionReturn(0);
27 }
28 
29 PetscErrorCode MatDuplicate_AIJCRL(Mat A, MatDuplicateOption op, Mat *M)
30 {
31   SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"Cannot duplicate AIJCRL matrices yet");
32 }
33 
34 PetscErrorCode MatSeqAIJCRL_create_aijcrl(Mat A)
35 {
36   Mat_SeqAIJ     *a      = (Mat_SeqAIJ*)(A)->data;
37   Mat_AIJCRL     *aijcrl = (Mat_AIJCRL*) A->spptr;
38   PetscInt       m       = A->rmap->n; /* Number of rows in the matrix. */
39   PetscInt       *aj     = a->j; /* From the CSR representation; points to the beginning  of each row. */
40   PetscInt       i, j,rmax = a->rmax,*icols, *ilen = a->ilen;
41   MatScalar      *aa = a->a;
42   PetscScalar    *acols;
43 
44   PetscFunctionBegin;
45   aijcrl->nz   = a->nz;
46   aijcrl->m    = A->rmap->n;
47   aijcrl->rmax = rmax;
48 
49   PetscCall(PetscFree2(aijcrl->acols,aijcrl->icols));
50   PetscCall(PetscMalloc2(rmax*m,&aijcrl->acols,rmax*m,&aijcrl->icols));
51   acols = aijcrl->acols;
52   icols = aijcrl->icols;
53   for (i=0; i<m; i++) {
54     for (j=0; j<ilen[i]; j++) {
55       acols[j*m+i] = *aa++;
56       icols[j*m+i] = *aj++;
57     }
58     for (; j<rmax; j++) { /* empty column entries */
59       acols[j*m+i] = 0.0;
60       icols[j*m+i] = (j) ? icols[(j-1)*m+i] : 0;  /* handle case where row is EMPTY */
61     }
62   }
63   PetscCall(PetscInfo(A,"Percentage of 0's introduced for vectorized multiply %g. Rmax= %" PetscInt_FMT "\n",1.0-((double)a->nz)/((double)(rmax*m)),rmax));
64   PetscFunctionReturn(0);
65 }
66 
67 PetscErrorCode MatAssemblyEnd_SeqAIJCRL(Mat A, MatAssemblyType mode)
68 {
69   Mat_SeqAIJ     *a = (Mat_SeqAIJ*)A->data;
70 
71   PetscFunctionBegin;
72   a->inode.use = PETSC_FALSE;
73 
74   PetscCall(MatAssemblyEnd_SeqAIJ(A,mode));
75   if (mode == MAT_FLUSH_ASSEMBLY) PetscFunctionReturn(0);
76 
77   /* Now calculate the permutation and grouping information. */
78   PetscCall(MatSeqAIJCRL_create_aijcrl(A));
79   PetscFunctionReturn(0);
80 }
81 
82 #include <../src/mat/impls/aij/seq/crl/ftn-kernels/fmultcrl.h>
83 
84 /*
85     Shared by both sequential and parallel versions of CRL matrix: MATMPIAIJCRL and MATSEQAIJCRL
86     - the scatter is used only in the parallel version
87 
88 */
89 PetscErrorCode MatMult_AIJCRL(Mat A,Vec xx,Vec yy)
90 {
91   Mat_AIJCRL        *aijcrl = (Mat_AIJCRL*) A->spptr;
92   PetscInt          m       = aijcrl->m; /* Number of rows in the matrix. */
93   PetscInt          rmax    = aijcrl->rmax,*icols = aijcrl->icols;
94   PetscScalar       *acols  = aijcrl->acols;
95   PetscScalar       *y;
96   const PetscScalar *x;
97 #if !defined(PETSC_USE_FORTRAN_KERNEL_MULTCRL)
98   PetscInt          i,j,ii;
99 #endif
100 
101 #if defined(PETSC_HAVE_PRAGMA_DISJOINT)
102 #pragma disjoint(*x,*y,*aa)
103 #endif
104 
105   PetscFunctionBegin;
106   if (aijcrl->xscat) {
107     PetscCall(VecCopy(xx,aijcrl->xwork));
108     /* get remote values needed for local part of multiply */
109     PetscCall(VecScatterBegin(aijcrl->xscat,xx,aijcrl->fwork,INSERT_VALUES,SCATTER_FORWARD));
110     PetscCall(VecScatterEnd(aijcrl->xscat,xx,aijcrl->fwork,INSERT_VALUES,SCATTER_FORWARD));
111     xx   = aijcrl->xwork;
112   }
113 
114   PetscCall(VecGetArrayRead(xx,&x));
115   PetscCall(VecGetArray(yy,&y));
116 
117 #if defined(PETSC_USE_FORTRAN_KERNEL_MULTCRL)
118   fortranmultcrl_(&m,&rmax,x,y,icols,acols);
119 #else
120 
121   /* first column */
122   for (j=0; j<m; j++) y[j] = acols[j]*x[icols[j]];
123 
124   /* other columns */
125 #if defined(PETSC_HAVE_CRAY_VECTOR)
126 #pragma _CRI preferstream
127 #endif
128   for (i=1; i<rmax; i++) {
129     ii = i*m;
130 #if defined(PETSC_HAVE_CRAY_VECTOR)
131 #pragma _CRI prefervector
132 #endif
133     for (j=0; j<m; j++) y[j] = y[j] + acols[ii+j]*x[icols[ii+j]];
134   }
135 #if defined(PETSC_HAVE_CRAY_VECTOR)
136 #pragma _CRI ivdep
137 #endif
138 
139 #endif
140   PetscCall(PetscLogFlops(2.0*aijcrl->nz - m));
141   PetscCall(VecRestoreArrayRead(xx,&x));
142   PetscCall(VecRestoreArray(yy,&y));
143   PetscFunctionReturn(0);
144 }
145 
146 /* MatConvert_SeqAIJ_SeqAIJCRL converts a SeqAIJ matrix into a
147  * SeqAIJCRL matrix.  This routine is called by the MatCreate_SeqAIJCRL()
148  * routine, but can also be used to convert an assembled SeqAIJ matrix
149  * into a SeqAIJCRL one. */
150 PETSC_INTERN PetscErrorCode MatConvert_SeqAIJ_SeqAIJCRL(Mat A,MatType type,MatReuse reuse,Mat *newmat)
151 {
152   Mat            B = *newmat;
153   Mat_AIJCRL     *aijcrl;
154   PetscBool      sametype;
155 
156   PetscFunctionBegin;
157   if (reuse == MAT_INITIAL_MATRIX) {
158     PetscCall(MatDuplicate(A,MAT_COPY_VALUES,&B));
159   }
160   PetscCall(PetscObjectTypeCompare((PetscObject)A,type,&sametype));
161   if (sametype) PetscFunctionReturn(0);
162 
163   PetscCall(PetscNewLog(B,&aijcrl));
164   B->spptr = (void*) aijcrl;
165 
166   /* Set function pointers for methods that we inherit from AIJ but override. */
167   B->ops->duplicate   = MatDuplicate_AIJCRL;
168   B->ops->assemblyend = MatAssemblyEnd_SeqAIJCRL;
169   B->ops->destroy     = MatDestroy_SeqAIJCRL;
170   B->ops->mult        = MatMult_AIJCRL;
171 
172   /* If A has already been assembled, compute the permutation. */
173   if (A->assembled) {
174     PetscCall(MatSeqAIJCRL_create_aijcrl(B));
175   }
176   PetscCall(PetscObjectChangeTypeName((PetscObject)B,MATSEQAIJCRL));
177   *newmat = B;
178   PetscFunctionReturn(0);
179 }
180 
181 /*@C
182    MatCreateSeqAIJCRL - Creates a sparse matrix of type SEQAIJCRL.
183    This type inherits from AIJ, but stores some additional
184    information that is used to allow better vectorization of
185    the matrix-vector product. At the cost of increased storage, the AIJ formatted
186    matrix can be copied to a format in which pieces of the matrix are
187    stored in ELLPACK format, allowing the vectorized matrix multiply
188    routine to use stride-1 memory accesses.  As with the AIJ type, it is
189    important to preallocate matrix storage in order to get good assembly
190    performance.
191 
192    Collective
193 
194    Input Parameters:
195 +  comm - MPI communicator, set to PETSC_COMM_SELF
196 .  m - number of rows
197 .  n - number of columns
198 .  nz - number of nonzeros per row (same for all rows)
199 -  nnz - array containing the number of nonzeros in the various rows
200          (possibly different for each row) or NULL
201 
202    Output Parameter:
203 .  A - the matrix
204 
205    Notes:
206    If nnz is given then nz is ignored
207 
208    Level: intermediate
209 
210 .seealso: MatCreate(), MatCreateMPIAIJPERM(), MatSetValues()
211 @*/
212 PetscErrorCode  MatCreateSeqAIJCRL(MPI_Comm comm,PetscInt m,PetscInt n,PetscInt nz,const PetscInt nnz[],Mat *A)
213 {
214   PetscFunctionBegin;
215   PetscCall(MatCreate(comm,A));
216   PetscCall(MatSetSizes(*A,m,n,m,n));
217   PetscCall(MatSetType(*A,MATSEQAIJCRL));
218   PetscCall(MatSeqAIJSetPreallocation_SeqAIJ(*A,nz,nnz));
219   PetscFunctionReturn(0);
220 }
221 
222 PETSC_EXTERN PetscErrorCode MatCreate_SeqAIJCRL(Mat A)
223 {
224   PetscFunctionBegin;
225   PetscCall(MatSetType(A,MATSEQAIJ));
226   PetscCall(MatConvert_SeqAIJ_SeqAIJCRL(A,MATSEQAIJCRL,MAT_INPLACE_MATRIX,&A));
227   PetscFunctionReturn(0);
228 }
229